        (if (< n (-count string)) (.charAt string n)))
     ([string n not-found]
        (if (< n (-count string)) (.charAt string n)
-           not_found)))
+           not-found)))
 
   goog.global.Array
   (-nth


  IStack
  (-peek [coll] first)
  (-pop [coll] (irest coll))

  ICollection
  (-conj [coll o] (List. meta o coll (inc count)))


(defn nil? [x]
  (identical? x nil))

(defn undefined? [x]
  (js* "(void 0 === ~{x})"))

(defn instance? [t o]
  (js* "(~{o} instanceof ~{t})"))
